Lua flavored Nginx rewrite or internal redirection cycle

Question

I'm new both to nginx and lua. I'm trying to follow this tutorial http://leafo.net/posts/creating_an_image_server.html#installation_requirements but for the life of me I can't get the nginx.conf right.

I've checked other questions similar to this where the problem is location, but I can't see what wrong with my code.

Here is the nginx.conf:

error_log stderr notice;
daemon off;

events { }

http {
  include /usr/local/openresty/nginx/conf/mime.types;

  server {
    listen 6789;
    lua_code_cache on;

    location @image_server {
      content_by_lua_file "serve_image.lua";
    }

    location ~ ^/images/(?<size>[^/]+)/(?<path>.*\.(?<ext>[a-z_]*))$ {
      root cache;
      try_files /$path @image_server;
    }

  }
}

And this is the serve_image.lua code

local sig, size, path, ext =

ngx.var.sig, ngx.var.size, ngx.var.path, ngx.var.ext local images_dir = "images/" -- where images come from local cache_dir = "cache/" -- where images are cached

local function return_not_found(msg)
  ngx.status = ngx.HTTP_NOT_FOUND
  ngx.header["Content-type"] = "text/html"
  ngx.say(msg or "not found")
  ngx.exit(0)
end

local source_fname = images_dir .. path
ngx.log(ngx.STDERR, "->>>>  " .. source_fname)

-- make sure the file exists
local file = io.open(source_fname)

if not file then
  ngx.log(ngx.STDERR, "Couldn't find the input file" .. source_fname)
  return_not_found()
end

file:close()

local dest_fname = cache_dir .. "/" .. size .. "/" .. path

-- resize the image
local magick = require("magick")
magick.thumb(source_fname, size, dest_fname)

ngx.exec(ngx.var.request_uri)

When I run the server I get a code 500.

This is the error in the terminal

rewrite or internal redirection cycle while redirect to named location "@image_server", client: 127.0.0.1, server: , request: "GET /images/80x80/wow.png HTTP/1.1", host: "localhost:6789"

I'm hoping a more experienced and fresh pair of eyes can point out what I'm doing wrong. Thanks.

Lua flavored Nginx rewrite or internal redirection cycle

0 Answers0